When choosing the shape of the attic, many homeowners choose the sloping mansard roof option, since choosing this option can most effectively distribute the space under the roof. Consider in more detail this option for the construction of the roof.
The roof is one of the most problematic places in the construction of any house. In order to choose the optimal shape of the roof, you will have to take into account not only the wishes of the developer, but also the technical characteristics of the building.
construction mansard roofs has recently become fashionable, since such a solution allows you to relatively inexpensively increase the area of \u200b\u200bthe house.
However, this work belongs to the category of complex, requiring careful calculations and strict adherence to building codes. Therefore, the construction of attics should be trusted only to professional builders with relevant experience.
Basic requirements for mansard roofs
The definition of attics is given in the regulatory document SNiP 2.08.01-89. According to the provisions of this document, the attic is considered to be the premises located in the attic space, the facade of which is a surface of an inclined or mansard roof.
In this case, the line on which the plane of the facade wall and the roof intersects should be located at a height not exceeding one and a half meters from the floor level in the attic floor rooms.
The attic floor can be located, occupying both the entire area of \u200b\u200bthe room, and part of it. The layout of the premises in the attic floor, as a rule, is associated with the structure of the main building and the premises below.
It is customary to subdivide attic floors into three types:
- One-level attic;
- Two-level attic;
- Attic with mezzanine floor.
The shape of the attic is determined by the shape of the roof. So, a sloping mansard roof allows you to create the most spacious room, the area of \u200b\u200bwhich can be used as efficiently as possible.
The main requirements for the construction of a mansard roof are its stability and strength. Therefore, it is necessary to carry out an engineering calculation of the mansard roof, which will take into account all the loads that will be placed on the structure.
As a rule, wooden beams are used for the construction of attic floors, so special attention should be paid to the fire safety of the future roof.
Building codes regulate the location of chimney channels, as well as special treatment of wooden structures with solutions that prevent ignition and the spread of fire.
In addition, wooden elements must be treated with antiseptic solutions that prevent the development of mold and insects.
What is a broken roof?
One of the varieties of gable roofs is a broken mansard roof. Moreover, this type of roof is one of the most difficult to perform.
This version of the roof device is best suited for converting the attic into a living space. The shape of such a roof suggests the presence of two unevenly inclined slopes, which are located on both sides of the building.
The main advantage of sloping roofs is the freedom of design. Such roofs can be made in a huge variety of options, that is, there is a real chance to make your home different from the rest.
As a rule, a mansard roof project involves the use of wooden beams to create truss trusses. A truss structure of such a roof is being built with the device of two broken slopes.
Do-it-yourself roof rafters, going below the corner of the inflection, are located at a steeper slope than the elements located above the named point.
The upper triangle of the structure is assembled from hanging rafters connected at the bottom with puffs. Moreover, these puffs simultaneously perform the function of the ceiling beams of the future premises.
Since the construction of broken roofs is very complex, mansard roof drawings should be carried out exclusively by specialists.
You should not rely solely on your practical construction experience, since a solid knowledge of design theory and the provisions of building codes is also necessary to create a competent project.
Design of sloping roofs
After the calculation of the attic roof is carried out, you can proceed to the implementation of the graphic part of the project, while taking into account the following factors:
- The geometry of the roof of the building, its shape and lines;
- The architecture of the designed attic, its design and decoration should be combined with the design of the main building;
- The project should provide for the installation of windows - inclined or vertical. The type and number of windows is selected depending on the overall architectural solution and the functional purpose of the room.
- When designing, it is important to carefully consider the choice of roofing, insulation and insulating materials.
Thus, a detailed drawing should be included in the project: a mansard roof, and its main components and structures.
Construction of mansard roofs
When performing installation work, the mansard roof construction technology regulated by building codes must be observed.The first stage of construction is the installation of a rafter structure.
For these purposes, lumber of the highest quality category is used, the moisture level of which does not exceed 22%.
Only in this case it is possible to assemble a structure that will be resistant to temperature extremes and atmospheric moisture. The rafter step depends on the angle of inclination and is in the range of 600-1200 mm.
Also, it is important to fulfill the following conditions:
- The lower level of the truss system is assembled from beams with a section of 250 mm. They are mounted in the form of parallel beams and fastened with cement mortar.
- Vertically located rafters are mounted from lighter bars with a cross section of at least 50 mm or boards with a width of at least 70 mm.
- For attaching vertical rafters to the lower beams, corners and high-strength bolts are used that meet the requirements of GOST 52644-2006
The next stage of construction is the installation of waterproofing.
To strengthen the film, it is convenient to use short rails that are overlapped, in the direction from the cornice to the roof ridge. The film is laid freely, without pulling it. Better if it sags a little.
Advice! To perform high-quality waterproofing, it is necessary to lay a double layer of film overlapping. The width of the film insertion is at least 20 mm. Separate layers are fastened with a special adhesive tape.
Next, collect the crate. For this, a beam with a section of 50 by 150 mm is useful. The step of laying the lathing depends on what type of roofing material is supposed to be used.
The choice of roofing material for a mansard roof
The choice of materials for roofing today is very diverse. But to cover mansard roofs, it is better to choose a material that has a small weight.
So, despite the undeniable advantages of natural or cement-sand tiles for attics, they are rarely used, since such a roof will have an impressive weight.
So, if a mansard roof is being installed, the most popular options are shingles or metal tiles.
Their advantages:
- Light weight;
- Relatively easy installation;
- High coating strength;
- External attractiveness and rich colors;
- incombustibility;
- Durability.
Mansard roof insulation
This stage of construction should be given special attention, since the comfort of using the attic space will depend on the quality of its implementation.
As a rule, the mansard roof insulation scheme is a structure consisting of several layers, in which, in addition to the insulation layer, a vapor barrier is included.
The vapor barrier is installed from inside the room and serves to protect against the penetration of moisture into the insulation, which accumulates in the room.
Thus, a correctly made design has the following composition (starting from inside the room):
- Finishing material;
- Sheets of plywood or drywall;
- Vapor barrier;
- insulation layer;
- Waterproofing;
- crate;
- Roofing material.
Typical mistakes in the construction of mansard roofs
The most common mistake in the construction of mansard roofs is a violation of the ventilation regime.
The fact is that well-planned ventilation ensures the correct operation of the entire “roofing pie”, therefore, with a lack or complete absence of ventilation, problems are inevitable.
The width of the gap between the insulation layer and the roof surface must be sufficient for effective ventilation.This value depends on the selected roofing material.
- When using profiled roofing materials, the size of the air gap should be at least 25 mm;
- When using flat sheet materials, the value of the ventilation layer is 50 mm.
A prerequisite is the device for ventilation in the ridge of the roof and in the eaves.
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